$ { {-3} \times \left[\begin{array}{rrr}{1} & {2} & {0} \\ {4} & {-1} & {-1}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-3}\times{1} & {-3}\times{2} & {-3}\times{0} \\ {-3}\times{4} & {-3}\times{-1} & {-3}\times{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-3} & {-6} & {0} \\ {-12} & {3} & {3}\end{array}\right]}$